This invention relates to the skinning of animals and more particularly, to a unique hog skinning apparatus and method.
Heretofore, the processing of hogs at a packing house has typically included the steps of killing and bleeding the hogs which are hung by their rear hocks in a head down position. Following the killing and bleeding, the hogs have usually been scalded, dehaired and singed. These steps are required for sanitary reasons prior to the actual butchering of the hogs. After these steps, the hogs have typically been split through their backbone or fat back area to form two equal halves or "hog sides", but in some instances without splitting the hide so that the entire skin would be kept intact. The main meat and bone portions were then removed from the hog sides. The residual meat, bacon, and fat are removed from the skin during the subsequent skinning process.
The skin of the hogs, when properly treated and if removed without damage, provides excellent material for shoes, purses, belts, and a wide variety of other goods. The packing or slaughterhouse owners, however, are not overly concerned with the condition of the skin but are more concerned with the complete removal of the valuable bacon.
Hog skinning machines have been developed for placement in the production line which remove the skin of the hog sides and optimize bacon yield without damage or with only minimal damage to the skin. Examples of such skinning machines may be found in commonly owned U.S. Pat. No. 3,744,407, issued July 10, 1973, in the name of Martin L. Harlan et al and entitled UNIVERSAL SINGLE SIDE SKINNING MACHINE and U.S. Pat. No. 3,310,085, issued Mar. 21, 1967, in the name of Paul F. Burch and entitled SKINNING MACHINE.
Machines of the type disclosed and discussed in the aforementioned U.S. patents, typically include a horizontally positioned, rotatable cylinder or drum having a longitudinally extending ditch within which the edge of the hog skin on a hog side is clamped. A skinning blade is positioned radially adjacent the cylinder periphery and functions to cut the meat, fat, and bacon from the skin as the cylinder rotates. These machines function quite effectively to remove the valuable bacon from the skin without damaging the skin of each hog side. However, these machines are incapable of removing the skin from the hog sides prior to removal of the meat and bone portions. These machines have also required sharp skinning blades to cut the skin from the meat.
Attempts have been made to develop apparatus capable of removing the skin from the hog carcass itself prior to cutting the hog into two halves at the fat back area. For example, German Patent 84,135 entitled VERTICAL DESIGN OF MACHINE FOR SKINNING HOGS, issued Aug. 20, 1971, in the name of Paul Pfretzschner et al. discloses an apparatus of removing the skin from a hog carcass suspended on a conveyor by the hog's rear hocks. The apparatus includes a drum supported on a frame in a substantially vertical position. The drum includes a longitudinally extending ditch within which a clamping apparatus is positioned. A skinning blade is mounted on a frame adjacent the periphery of the drum. In use, an edge of the hog skin, after preliminary cutting, is manually laid in the open ditch of the drum and clamped therein. As the drum rotates, the hog also rotates and the skinning blade slices the skin from the hog carcass.
It has been found, however, that the machine of the type disclosed in the aforementioned German Patent suffers from deficiencies relating to sanitation capability, to safety of operation to workmen, to the clamping action, to the positioning of the skin flap within the ditch, and to the control of the skinning blade, thus preventing it from being a useful, practical machine capable of meeting sanitation and labor safety standards.
Because the drum and ditch are generally vertically oriented on the German machine, it is rather difficult and dangerous to manually place the skin flap in the ditch for clamping, as opposed to the horizontal hog side skinner where the flap will lay down into the ditch. Also the vertical skin flap tends to be wrinkled diagonally because of its orientation. Such a wrinkle, when clamped, prevents effective clamping of the skin and also causes the blade to cut through the skin and ruin it as the skinning proceeds.